Internal combustion engine pollution control device

ABSTRACT

A pollution control device for automobile engines and the like is provided having a housing adapted to receive the blowby gasses from the engine crankcase. The housing has a filter assembly for filtering the blowby gasses and inlet means for mixing the gasses with air to increase oxidation of the pollutants in the gasses. The treated gasses are supplied to the engine intake manifold through the positive crankcase ventilation valve. Alternative embodiments of the invention provide for heating the blowby gasses in the housing, eliminating the need for the positive crankcase ventilation valve, and for sonic mixing of the air and blowby gasses in the housing.

[ 1 Dec. 18, 1973 1,809,359 8/1969 Germany 55/445 233,641 4/1911 Germany........ 123/119 B Primary Examiner-Wendell E. Burns Attorney-Robert A. Maikis [57] ABSTRACT A pollution control device for automobile engines and the like is provided having a housing adapted to receive the blowby gasses from the engine crankcase. The housing has a filter assembly for filtering the blowby gasses and inlet means for mixing the gasses with air to increase oxidation of the pollutants in the gasses. The treated gasses are supplied to the engine INTERNAL COMBUSTION ENGINE POLLUTION CONTROL DEVICE Inventor: Joseph J. Gartner, 506 Queen Anne Rd., Teaneck, NJ. 07666 Filed: Nov. 23, 1971 Appl. No; 201,351

US. 123/119 B, 55/444, 55/445 Int. F02m 25/06, BOld 45/00 Field of Search................... 123/119 B; 55/442, 55/443, 444, 445, 446

References Cited UNITED STATES PATENTS United States Patent Gartner 12 Claims, 11 Drawing Figures intake manifold through the positive crankcase ventilation valve. Alternative embodiments of the invention provide for heating the blowby gasses in the housing, eliminating the need for the positive crankcase ventilation valve, and for sonic mixing of the air and blowby gasses in the housing.

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, fi-M ATTORNEY INTERNAL COMBUSTION ENGINE POLLUTION CONTROL DEVICE BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to air pollution control equipment and more particularly to a pollution control device for internal combustion engines for automobiles and the like. I

2. Description of the Prior Art Automobile internal combustion engines have frequently been identified as a major source of air pollution at the present time. During the combustion process in the cylinders of the engine, various pollutants are formed and released into the atmosphere. The pollutants which cause the greatest concern are unburned hydrocarbons, carbon monoxide, various oxides of nitrogen, and particulates, such as lead, for example. The pollutants reach the atmosphere from several sources in the vehicle. Vapor from the fuel in the vehicle tank and vapor from the carburetor produce a small but definite amount of pollution. The exhaust from the engine produces a large amount of airborne pollutants. A substantial amount of pollutants, however, arise from crankcase emissions.

The crankcase emissions are derived in large part from so called blowby gasses which escape past the piston rings in the engine cylinders during the power stroke. When the mixture of fuel and air in each cylinder is ignited by the spark plug, the gasses and particulates which are formed in the cylinder are blown past the piston rings and into the crankcase. Apart from particulates, such as lead, for example, the blowby gasses include unburned hydrocarbons, carbon monoxide and various oxides of nitrogen.

In order to minimize the pollution caused by emission of crankcase gasses, a system of positive crankcase ventilation was developed in which the blowby gasses from the crankcase were routed back into the engine combustion chambers through the engine intake manifold. Since the routing of the blowby gasses into the cylin-. ders produced a vacuum in the crankcase during engine operation, a filtered air inlet was also provided to admit fresh air to ventilate the crankcase. A valve, usually called the PCV valve, in the blowby tube serves to adjust the flow of blowby gasses to the flow of the air-fuel mixture delivered by the carburetor and to prevent the air-fuel mixture from being drawn into the crankcase. Although this system functions to remove a large part of the pollutants normally admitted to the atmosphere by crankcase emissions, it is not entirely satisfactory because a large part of the recycled pollutants are not burned in the engine cylinders but are merely passed to the atmosphere through the exhaust system of the engine. Unless the engine is given repeated tune ups" and other maintenance, the unburned hydrocarbons, carbon monoxide and oxides of nitrogen present in the blowby gasses are not materially affected by reburning in the combustion cylinders. Furthermore, particulates, such as lead, are merely fed back into the engine cylinders and eventually reach the atmosphere through the exhaust system. The time and expense involved in repeated engine tune ups and other maintenance procedures discourage automobile owners from keeping their vehicles in a relatively non-polluting state and permit crankcase emissions to remain high on the list of automobile engine pollution sources.

SUMMARY OF THE INVENTION It is an object of this invention to provide a pollution control device for reducing the airborne pollutants derived from crankcase emissions of automobile internal combustion engines and the like which is effective without repeated engine tune ups and other costly maintenance.

It is a further object of this invention to provide an internal combustion engine pollution control device which is adapted for use on a wide variety of commercially-available automobiles and other vehicles and which is easily installed by the average automobile owner.

It is a still further object of this invention to provide an automobile engine pollution control device which is especially adapted for use on vehicles equipped with positive crankcase ventilation.

It is an additional object of this invention to provide an automobile engine pollution control device which maintains its effectiveness over long periods of time and which requires minimum maintenance.

It is an additional object of this invention to provide an automobile engine pollution control device which is mechanically rugged in construction, trouble-free in operation, and of relatively small size and weight.

Briefly, the pollution control device of the invention comprises a hollow housing having an inlet opening adapted to be coupled to the crankcase of an engine to receive the blowby gasses therefrom. The housing has an outlet opening which is adapted to be coupled to the intake manifold of the engine and an air inlet passageway disposed between the inlet and outlet openings for supplying air to the blowby gasses in the housing. A mechanical filter assembly is disposed in the housing between the inlet and outlet openings for filtering the blowby gasses to remove the pollutants therefrom. Alternative embodiments of the invention contemplate means for heating the blowby gasses in the housing, a filter assembly which permits the PCV valve to be eliminated, and the addition of a sonic mixing chamber to the housing for mixing the air and blowby gasses therein.

The nature of the invention and other objects and additional advantages thereof will be more readily understood by those skilled in the art after consideration of the following detailed description taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a full sectional view of an automobile engine pollution control device constructed in accordance with the teachings of the present invention;

FIG. 2 is a plan view of a filter plate used in the filter assembly of the device shown in FIG. 1;

FIG. 3 is a full sectional view of the filter plate of FIG. 2 taken along the line 3-3 of FIG. 2;

FIG. 4 is a plan view of an end plate used in the filter assembly of the device shown in FIG. 1 of the drawings;

FIG. 5 is a side elevational view of an automobile engine pollution control device constituting an alternative embodiment of the invention with portions of the device broken away to reveal details of construction;

FIG. 6 is an exploded perspective view of a filter assembly for the pollution control device of the invention utilizing an alternative end plate construction;

FIG. 7 is a full sectional view of the filter assembly of FIG. 6 taken along the line 77 in FIG. 6;

FIG. 8 is an end elevational view of a filter assembly which utilizes a novel end plate construction which permits the PCV valve to be eliminated in most automobile engines;

FIG. 9 is a full sectional view of the filter assembly shown in FIG. 8 taken along the line 99 in FIG. 8;

FIG. 10 is an exploded perspective view of an automobile engine pollution control device constructed in accordance with the present invention which utilizes a sonic mixing chamber; and

FIG. 11 is a full sectional view of the sonic mixing chamber of FIG. 10 taken along the line 1 1-11 of FIG. 10.

DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION Referring now to FIG. 1 of the drawings, there is shown an automobile engine pollution control device constructed in accordance with the teachings of the present invention. The device comprises a cylindrical housing which is provided with a circular cover 21 at the upper end thereof. The lower end 22 of the housing is provided with an inwardly-extending, cylindrical end portion 23 which has a concentric opening 24 formed therein. A cylindrical mounting flange 25 is seated in the opening 24 and has a flange or rim portion 26 upon which the lower end 22 of the housing is seated. The mounting flange 25 is provided with a cylindrical bore or chamber 27 which is internally threaded at the lower end thereof to receive one end of an externally threaded pipe nipple 28. The other end of the nipple 28 is screwed into a threaded opening 29 which is formed in the wall 30 of the engine exhaust manifold 31,'so that the housing 20 is removably supported on the manifold 31 by means of the mounting flange 25 and pipe nipple 28. The pipe nipple 28 provides a communicating passageway between the exhaust manifold 31 and the chamber 27 in the mounting flange, so that the hot exhaust gasses from the manifold are permitted to circulate in the chamber for reasons which will be hereinafter explained.

The cover 21 of the housing is provided with an internally threaded opening 32 which receives a threaded hose fitting 33. A hose 34 of rubber or other suitable material serves to connect the threaded hose fitting 33 to an externally threaded hose fitting 35 on the automobile engine PCV valve 36. The PCV valve 36 is mounted on a tee fitting 37 which is connected to the intake manifold (not shown) of the engine. The side wall of the housing 20 is provided with an internally threaded opening 38 which receives a threaded hose fitting 39. A flexible hose of rubber or other suitable material has one end thereof connected to the hose fitting 39 and the other end thereof connected to a hose fitting 41 which acts to couple the hose to the blowby gas output 42 of the engine crankcase. The cylindrical side wall of the housing 20 is also provided with a threaded opening 43 which receives a threaded pipe fitting 44..The fitting 44 has an internal bore 45 which serves to connect the interior of the housing 20 to the atmosphere. The fitting 44 functions as an air inlet passageway for the housing 20 and to that end is provided with a threaded cap 46 which serves to hold a wire-mesh screen 47 in place against the external end of bore 45 to prevent foreign matter from entering the housing. A bushing 48, having a relatively small bore, is press fitted into the bore 45 of the fitting to limit the flow of air into the housing" 20. The wire-mesh screen 47 may, for example, comprise a No. 80 aluminum screen while the bushing 48 may have an internal diameter of 0.092 inches. The lower end of the cylindrical side wall of the housing 20 is also provided with a threaded aperture 49 which receives a threaded pipe fitting 50. The pipe fitting 50 serves as admin to remove condensate from the interior of the housing and is provided with a drain block or plug 51.

As thus far described, it is believed apparent that the blowby gasses from the engine crankcase are conducted to the interior of the housing 20 by means of the blowby fitting 42 and the hose 40. The gasses are then passed through a filter assembly, indicated generally as 52, to the upper portion of the housing interior, where they are conveyed by means of the hose 34 and the PCV valve 36 to the engine intake manifold. The filter assembly 52 consists of a plurality of circular filter plates 53 and two circular end plates 54 which are removably mounted on a vertical rod or shaft 55. The shaft 55 extends through an opening 56 formed in the face of the inwardly-extending portion 23 of the housing. The lower end 57 of the shaft threadedly engages a tapped bore 58 formed in the upper end of the mounting flange 25, so that the shaft 55 is supported in a vertical position and is secured to the mounting flange. The upper end of the shaft 55 extends through an opening 59 formed in the cover 21 of the housing and terminates in a threaded end portion 60 which receives a wing nut 61 to hold the cover in place. The filter plates 53 and the end plates 54 of the filter assembly are separated from each other and are spaced from the housing projection 23 and the cover 21 of the housing by means of cylindrical bushings 62 which are concentrically disposed on the shaft 55. It will be noted that the filter assembly 52 is disposed in the path of the blowby gasses as they pass through the housing from the engine crankcase to the PCV valve 36.-

The detailed construction of the filter plates 53 is shown in FIGS. 2 and 3 of the drawings, wherein it is seen that each plate is circular in shape and is provided with a central opening 63 which receives the shaft 55. Each of the filter plates 53 has an outside diameter which is about 0.010 inch smaller than the inside diam eter of the cylindrical housing 20. This spacing not only permits the filter plates 53 to be inserted into the housing 20 but also serves to provide a small filter opening for the blowby gasses which are forced through the filter assembly. Each of the filter plates 53 is also provided with a plurality of radially-extending slots or openings 64 which are formed in the plates by fingers 65. Each of the fingers 65 may be conveniently formed by making two parallel cuts in the plate which extend inwardly a distance from the periphery and bending the resultant finger outwardly from the plane of the plate to form the filter openings 64. Since the radial cuts which are made do not extend all the way from the periphery of the plate to the aperture 63, the fingers may be bent outwardly leaving an annular flat space or face" 66 for the seating of the spacers 62. The filter slots or openings 64 are preferrably 0.0l0 inch in width to provide the required filtering action. The end plates 54 of the filter assembly 52 are shown in FIG. 4 of the drawings as having a centrally-disposed aperture 67 which receives the shaft 55 of the filter assembly. A

plurality of notches 68 are provided around the periph ery of the plate and the central portion of the plate is provided with a series of openings 69. Neither of the end plates 54 perfrom any filtering action. The end plates are made slightly larger in diameter than the filter plates 53 so that the end plates serve to center the filter assembly in the cylindrical interior of the housing 20. The notches 68 and the openings 69 in the end plates are made sufficiently large to permit cleaning of the assembled stack of filter elements by a blast of compressed air or by reverse flushing the filter with gasoline or other suitable cleaning fluid. It should be noted that the total filtering area provided by the slots 64 of the filter plates 53 and by the clearances between the filter plates and the inside diameter of the housing should be at least equal to the cross-sectional area of the output line from the housing 20, so that a back pressure is not caused to build up which could adversely affect engine operation.

During engine operation, the pollution control device shown in FIGS. 1 through 4 of the drawings receives the blowby gasses from the crankcase of the engine. These gasses, 'as explained previously, contain unburned hydrocarbons, carbon monoxide, oxides of nitrogen and particulates, such as lead, for example. The

- mixture of hot gasses and particulates passes through the filter assembly 52 where the particulates are largely filtered out by passage of the mixture through the slots 64 and the clearances between the filter plates 53 and the interior wall of the housing 20. The mounting flange serves as a heat exchanger to heat the blowby gasses from the hose 40 when they are admitted to the housing interior. The chamber 27 in the mounting flange communicates directly with the exhaust manifold of the engine so that a large heat source is available for the heating of the blowby gasses. At the same time, the air inlet assembly 44 functions to admit air to the interior of the housing in controlled amounts. By virtue of this combined action, large particles of unburned hydrocarbon are deposited on the filter plates and the carbon monoxide present is largely converted to the less harmful form of carbon dioxide. Similarly, it is believed that the oxides of nitrogen present in the blowby gasses break down into nitrogen and oxygen more readily then would have occured had the blowby gasses been supplied directly to the combustion chamber of the engine without passing through the filter of the invention. in any event, operation of an engine equipped with the pollution control device of the invention over several thousand operating miles will produce a rather large quantity of liquid in the bottom of the housing 20. This liquid contains the filtered-out particulates, the unburned hydrocarbons and the absorbed carbon dioxide. Accordingly, the PCV system of the engine is permitted to operate more efficiently because the pollutants in the blowby gasses removed and/or converted to less harmful forms by the pollution control device of the invention. Consequently, the need for repeated and expensive engine tune-ups to maintain the PCV system in good operating condition is largely eliminated and the pollutants in the engine exhaust reduced in quantity.

It will be noted that the construction of the disclosed device permits the entire housing 20 to be readily removed for cleaning by unscrewing the threaded shaft 55 so that the housing is no longer secured to the mounting flange 25. With the housing removed, the exhaust manifold is still sealed because the chamber 27 does not communicate with the atmosphere. Similarly, the cover 21 of the unit may be removed by means of the wing nut 61 so that the entire filter assembly 52 can be withdrawn for easy cleaning. The maintenance of the filter is relatively simple since the design of the filter plates permits the trapped pollutants to gather in liquid form at the bottom of the housing 20. The gathered liquid is then easily withdrawn through the drain plug 51.

In practice, the housing 20, cover plate 21, filter plates 53 and end plates 54 may be fabricated of aluminum or any other suitable material which will withstand the high operating temperatures involved and which will not chemically react with the matter in the blowby gasses. The hose fittings 33 and 39, the air inlet assembly 44, the drain plug assembly 50 and the pipe nipple 28 are preferably fabricated of brass or other material which exhibits a relatively high structural strength and which will not react with the pollutants in the blowby gasses. The mounting flange 25 should have a high degree of structural strength and should obviously have a high coefiicient of heat transfer. Accordingly, the mounting flange may, for example, be fabricated of brass or aluminum. It will be noted that the filter plates 53 of the device may be easily fabricated by stamping them from sheet aluminum. The entire filter assembly may be assembled and inserted in the housing 20 by relatively unskilled labor because the end plates 54 act as a guide for insertion of the assembly and provide the correct filter clearances between the filter plates- 53 and the walls of the housing 20. Finally, it is believed apparent that the design of the pollution control device of the invention permits the device to be easily installed in many of the different types of automobiles on the road today by the average automobile owner. For automobiles equipped with the PCV system of crankcase emission control, it is only necessary to break the connection of the blowby hose 42 to the PCV valve 36 and insert the unit by means of the provided hose fittings. The installation of the unit on the exhaust manifold 31 merely requires the drilling and tapping of a suitable opening in the manifold.

For automobiles of the 1969 model year and later, the embodiment of the invention shown in FIG. 5 of the drawings may be utilized. This embodiment of the invention differs from that shown in FIGS. 1 through 4 of the drawings in that the heat exchanger unit is eliminated so that the pollution control device need not be connected to the exhaust manifold. The housing of the device is formed by a cylindrical shell which may be fabricated of spun or cast aluminum, for example. The shell 70 is provided with a hose fitting 71 which has a bore 72 that communicates with the interior 73 of the housing. The hose fitting 72 includes a portion 74 of re duced diameter which has been foreshortened for convenience of illustration. Shoulder portions 75 and 76 are formed on the two portions of the hose fitting 71, so that the fitting will accommodate hoses of different diameter thereby enabling the device to be used with a wider variety of commercially-available automobiles. The fitting 71 is adapted to be connected to the blowby hose leading from the crankcase of the vehicle. The

housing also consists of a second cylindrical shell 77 which is concentrically disposed in the housing portion 70. Shell 77 is provided with a hose fitting 78 which is similar in design to the hose fitting 71 and which contains a passageway 79 communicating with the interior 73 of the housing. This hose fitting is adapted to be connected to the hose leading to the PCV valve of the engine.

In FIG. of the drawings, the central axis XX of the housing assembly is shown in a vertical position for convenience of illustration. In practice, however, the

XX axis would be substantially horizontal to permit drainage of the condensate in the housing to a storage container 80. To this end, the housing portion 70 is provided with a hose fitting 81 which communicates with the interior 73 of the housing and which is adapted to receive one end of a drain hose 82. The other end of the hose 82 is secured to a hose fitting 83 located in the top of the container 80. Hose clamps 84 are employed to insure a good connection of the hose 82 to the fittings 81 and 83. With the XX axis of the housing in a substantially horizontal position, the condensate forming in the interior 73 of the housing will drain by gravity through the hose 82 into the storage container 80. In this embodiment of the invention, the filter assembly 85 is again made up of the filter plates and end plates shown in FIGS. 2, 3 and 4 of the drawings. The plates are, however, held together by a short bolt 86 and a nut 87 so that the entire filter assembly may be slidably removed from the interior 73 of the housing. The air inlet for this embodiment of the invention is considerably simplified in that it may comprise a hole 88 drilled through both the housing portions 70 and 77. The drilled or otherwise formed hole 88 may, for example, be 0.062 inch in diameter.

The embodiment of the invention shown in FIG. 5 of the drawings should be of considerably smaller size than the embodiment shown in FIG. 1 of the drawings. The smaller size of the housing in the arrangement of FIG. 5 permits a much smaller amount of heat tobe radiated or otherwise lost to the atmosphere, thereby providing a higher operating temperature for the entire unit. The reduced loss permits the heat exchanger shown in FIG. 1 of the drawings to be eliminated and materially simplifies the construction of the unit. The embodiment of the invention shown in FIG. 1 of the drawings with a heat exchanger would be especially adapted for use on 1968 or earlier model automobiles which are not provided with a thermostaticallycontrolled air heater for the carburetor air intake. The embodiment shown in FIG. 5 would be suited for use with the I969 and later model automobiles which are provided with air intake heaters. In practice, housing portions 70 and 77 may be easily fabricated of aluminum while the container 80 may comprise a simple plastic container which is easily emptied by the automobile owner. In all other respects, however, the operation of this embodiment is the same as the embodiment shown in FIG. 1 of the drawings. If desired, the container 80 may be formed of a transparent or translucent material so that the level of accumulated fluid may be easily noted by the motorist and emptied at regular intervals. It may also be noted that the pollution control device shown in FIG. 5 of the drawings could be operated with the XX axis of the housing in a substantially vertical position if the assembly were so oriented that the hose fitting 81 was disposed at the bottom of the housing so that accumulated fluids could drain by gravity into the container 80.

An exploded perspective view of the filter assembly 85 is shown in FIG. 6 of the drawings wherein reference characters with a prime notation are employed to identify elements which are the same as or similar to the correspondingly numbered elements in FIGS. 1 through 4. The filter plates 53' are basically the same as the filter plates 53 in FIG. 2 of the drawing except that they are of smaller diameter. The end plates in this filter assembly are basically the same as the filter plates 53 and may be made on the same production equipment. However, each of the end plates 90 is provided with a plurality of notches 91 about the periphery thereof so that neither end plate performs any filtering function. The notches 91 in each end plate permit the filter assembly to be cleaned by reverse flushing or compressed air blasts. They also permit any condensate trapped by the filter plates 53 to drain into the portion of the housing adjacent the hose fitting 81. Although this type of end plate does not provide the support and guide functions of the end plate shown in FIG. 4 of the drawings because its diameter is the same as the filter plates 53', it does offer the advantage that it may be made on the same production machines used for the filter plates thereby minimizing production costs. A completely assembled stack of the filter plates 53 and end plates 90 is shown in'FIG. 7 of the drawings. It may be noted that the overall operating efficiency of the filter assembly depends upon the number of filter plates employed. Since the filter plates 53 employed in the embodiment of FIG. 5 of the drawings are generally of much smaller diameter than the filter plates 53 employed in the embodiment of FIG. 1 of the drawings, a larger number of plates should be utilized to provide the same filter area.

FIGS. 8 and 9 of the drawings illustrate a modified filter assembly which performs the check valve" function of the PCV valve in the automobile engine. As explained previously, the PCV valve prevents the air and fuel mixture in the engine intake manifold from being drawn back into the crankcase during operation of the engine. In the filter assembly shown in FIGS. 8 and 9, the filter plates 53', spacers 62', bolt 86 and nut 87 are the same as the corresponding elements shown in FIG. 6 of the drawings. In this embodiment, one of the end plates 92 is provided with a plurality of radiallydisposed apertures 93. A leaf spring arrangement 94 having a plurality of radially-disposed fingers 95 is placed over the end plate 92 and secured in the filter stack by the bolt 86 and nut 87. The fingers 95 of the leaf spring are disposed over the apertures 93 in the end plate 92. Each of the fingers 95 is provided with a bent or crimped portion 96 so that the finger is securely pressed against the surface of the plate 92, to thereby effectively seal the apertures. 93. The diameter of the end plate 92 is then made large enough so that the plate effectively provides a relatively gas-tight barrier across the housing portion 77 of thedevice. The filter assembly is then inserted into the housing portion so that the end plate 92 is adjacent the hose fitting 78 which leads to the engine intake manifold. The direction of flow of the blowby gasses through the filter assembly is shown in FIG. 9 of the drawings by the arrow 97. From an inspection of this figure, it is believed apparent that the pressure exerted by the blowby gas flow will lift the fingers 95 of the leaf spring assembly and permit the filtered gasses to be applied to the intake manifold. When a reverse flow occurs, however, the fingers 95 are forced against the openings 93 in the plate 92 so that the air-fuel mixture in the intake manifold is not drawn back into the engine crankcase. Accordingly, this embodiment of the filter assembly effectively permits the elimination of the check valve function of the PCV valve in the automobile engine. This embodiment of the invention could therefore be employed on early model automobiles which are not provided with positive crankcase ventilation systems. For new cars, this modification of the filter'assembly could effectively permit the elimination of the PCV valve.

FIGS. 10 and 11 of the drawings illustrate a modification of the pollution control device of the invention which provides for sonic mixing of the blowby gasses and the air drawn into the filter housing during operation. In describing this modification of the invention, reference characters with a prime notation will be employed to identify components which are the same as or similar to the correspondingly numbered components in FIG. 5 of the drawings. As seen in FIG. 10, a baffle element 100 is disposed in the housing portion 77' which leads to the engine PCV valve. The bafile which is truncated at one end thereof to provide a cylindrical shoulder portion 103. The shoulder portion 103 has an opening 104 formed therein which is counterbored at end 105 thereof to produce a larger diameter passageway leading into the output hosefitting 78'. The input side of the baffle 100 is closed with a dished circular plate 106 which has an opening 107 formed therein. The dished plate 106 may be secured to the end 108 of the shell 102 by any convenient means, such as swaging, for example. This arrangement forms a sonic mixing cavity or chamber 109 in the baffle in which the air from the air inlet opening 88 is mixed with the filtered blowby gasses. The larger diameter aperture 107 in the plate 106 cooperates with the smaller diameter opening 104 in the shoulder portion 103 to provide a venturi arrangement. The inlet air and the blowby gasses circulate in the cavity 109 and generate sonic waves which greatly enhance the mixing function, so that more oxygen is made available to the carbon monoxide pollutants to more readily convert them to carbon dioxide If desired, a number of small openings 110 may be provided in the dished plate 106 to facilitate drainage of any condensates trapped in the cavity 109. Although it is believed that the dimensions of the apertures 104 and 107 are not critical, it has been found that a diameter of 5/32 inch for the opening 104 and a diameter of 7/32 inch for the opening 107 will provide and adequate sonic mixing effect when the distance between the apertures ranges from 0.210 inch to 0.280 inch.

It is believed apparent that many changes could be made in the construction and described uses of the foregoing pollution control device and many seemingly different embodiments of the invention could be constructed without departing from the scope thereof. Accordingly, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

l. A pollution control device for internal combustion engines having a positive crankcase ventilation valve comprising a hollow housing having an inlet opening adapted to be coupled to the crankcase of said engine to receive the blowby gasses therefrom, an outlet opening adapted to be coupled to said positive crankcase ventilation valve of the engine, and an air inlet passageway for supplying air to the blowby gasses; and

a mechanical filter assembly disposed in said housing between said inlet and outlet openings for filtering the blowby gasses to remove the pollutants therefrom.

2. A pollution control device as claimed in claim 1 further comprising means adapted to be coupled to the exhaust manifold of the engine for heating the blowby gasses in said housing.

3. A pollution control device as claimed in claim 2 wherein said filter assembly comprises a stack of spaced filter 1 plates, each of said filter plates having a plurality of spaced filter apertures therein,

said housing has an inwardly projecting wall portion defining a cavity therein, and

said heating means comprises a heat exchanger removably disposed in said cavity.

4. A pollution control device as claimed in claim 1 wherein said filter assembly comprises a shaft member,

a stack of spaced filter plates slidably disposed on said shaft member for support thereby, each of said filter plates having a plurality of radially-disposed filter slots formed therein, and v a pair of end plates slidably disposed on said shaft member for support thereby at opposite ends of said stack of filter plates.

5. A pollution control device fingers claimed in claim 4 wherein said filter slots are formed by a plurality of radially-disposed fingers cut from the filter plate to leave a plurality of radially-disposed slotted openings in the plate, each of said fingers being supported at one end thereof by the plate and being spaced a distance from the plane of the plate, so that the radiallydisposed edges of the ingers cooperate with said slotted openings to form the filter slots.

6. A pollution control device as claimed in claim 4 wherein each of said end plates has a larger area than the area of each of said filter plates, so that the filter assembly is centered in said housing by the end plates, said end plates being provided with openings having an area considerably larger than the area of said filter plates so that the filter assembly may be cleaned by the passage of a cleaning fluid therethrough.

7. A pollution control device as claimed in claim 5 wherein each of said end plates is formed by one of said filter plates and has a plurality of notches formed about the periphery thereof to permit cleaning of the filter assembly and drainage of the condensate therefrom.

8. A pollution control device as claimed in claim 4 wherein one of said end plates has a plurality of radially-disposed apertures formed therein and a leaf spring having a plurality of radially-disposed fingers is provided to seal the apertures, so that gas flow through the filter assembly is limited to one direction.

9. A pollution control device as claimed in claim 1 further comprising a sonic mixing chamber disposed in said housing for mixing the blowby gasses with the air from said air inlet passageway, said mixing chamber having a passageway with a throat portion of reduced crosssectional area which is adapted to receive the blowby gasses and air. 10. A pollution control device as claimed in claim 6 wherein said hollow housing is provided with a drain opening,

and g a closed storage container is connected to said drain opening to receive pollutants filtered from said blowby gasses. 11. A pollution control device as claimed in claim 10 wherein said hollow housing is cylindrical,

said filter plates and end plates are circular, and

said inlet opening and outlet opening are formed by cylindrical hose fittings disposed at opposite ends of said housing.

12. A pollution control device as claimed in claim 11 wherein each of said radially-disposed filter slots is approximately'0.0l0 inch wide, and

the total filtering area provided by said filter slots and the clearance between said stack of filter plates and the inside diameter of said housing is at least equal to the cross-sectional area of said outlet opening, so that no back pressure is formed during operation of the device. 

1. A pollution control device for internal combustion engines having a positive crankcase ventilation valve comprising a hollow housing having an inlet opening adapted to be coupled to the crankcase of said engine to receive the blowby gasses therefrom, an outlet opening adapted to be coupled to said positive crankcase ventilation valve of the engine, and an air inlet passageway for supplying air to the blowby gasses; and a mechanical filter assembly disposed in said housing between said inlet and outlet openings for filtering the blowby gasses to remove the pollutants therefrom.
 2. A pollution control device as claimed in claim 1 further comprising means adapted to be coupled to the exhaust manifold of the engine for heating the blowby gasses in said housing.
 3. A pollution control device as claimed in claim 2 wherein said filter assembly comprises a stack of spaced filter plates, each of said filter plates having a plurality of spaced filter apertures therein, said housing has an inwardly projecting wall portion defining a cavity therein, and said heating means comprises a heat exchanger removably disposed in said cavity.
 4. A pollution control device as claimed in claim 1 wherein said filter assembly comprises a shaft member, a stack of spaced filter plates slidably disposed on said shaft member for support thereby, each of said filter plates having a plurality of radially-disposed filter slots formed therein, and a pair of end plates slidably disposed on said shaft member for support thereby at opposite ends of said stack of filter plates.
 5. A pollution control device fingers claimed in claim 4 wherein said filter slots are formed by a plurality of radially-disposed fingers cut from the filter plate to leave a plurality of radially-disposed slotted openings in the plate, each of said fingers being supported at one end thereof by the plate and being spaced a distance from the plane of the plate, so that the radially-disposed edges of the ingers cooperate with said slotted openings to form the filter slots.
 6. A pollution control device as claimed in claim 4 wherein each of said end plates has a larger area than the area of each of said filter plates, so that the filter assembly is centered in said housing by the end plates, said end plates being provided with openings having an area considerably larger than the area of said filter plates so that the filter assembly may be cleaned by the passage of a cleaning fluid therethrough.
 7. A pollution control device as claimed in claim 5 wherein each of said end plates is formed by one of said filter plates and has a plurality of notches formed about the periphery thereof to permit cleaning of the filter assembly and drainage of the condensate therefrom.
 8. A pollution control device as claimed in claim 4 wherein one of said end plates has a plurality of radially-disposed apertures formed therein and a leaf spring having a plurality of radially-disposed fingers is provided tO seal the apertures, so that gas flow through the filter assembly is limited to one direction.
 9. A pollution control device as claimed in claim 1 further comprising a sonic mixing chamber disposed in said housing for mixing the blowby gasses with the air from said air inlet passageway, said mixing chamber having a passageway with a throat portion of reduced cross-sectional area which is adapted to receive the blowby gasses and air.
 10. A pollution control device as claimed in claim 6 wherein said hollow housing is provided with a drain opening, and a closed storage container is connected to said drain opening to receive pollutants filtered from said blowby gasses.
 11. A pollution control device as claimed in claim 10 wherein said hollow housing is cylindrical, said filter plates and end plates are circular, and said inlet opening and outlet opening are formed by cylindrical hose fittings disposed at opposite ends of said housing.
 12. A pollution control device as claimed in claim 11 wherein each of said radially-disposed filter slots is approximately 0.010 inch wide, and the total filtering area provided by said filter slots and the clearance between said stack of filter plates and the inside diameter of said housing is at least equal to the cross-sectional area of said outlet opening, so that no back pressure is formed during operation of the device. 